Make a complaint to the airline address it to the President, and show them the glass, document it but keep the glass. If you can picture them do it, and most of all show them the cut in your tongue. Your seatmate should be a handy companion if he attest your fate. PR catering services is Macro Asia, its subsidiary. I'm sure compensation should follow if you did it while you are still in the air. If not, then forget about the compensation thing. You may have to bring them to courts, but in a nice way you can still notify them. Who knows what's up their sleeves?
My experienced recently with Pal on board meal was a piece of a shoulder tip hair in my meal tray..and i have the feeling it came from the serving female flight attendant because her hair is not in a pinned ponytail.